1. Field of the Invention
The present invention relates to an apparatus for separating liquid and associated liquid vapor from a gas stream and, more particularly, to such an apparatus utilizing calcium chloride as a desiccant.
2. Description of the Prior Art
Natural gas is a mixture of hydrocarbon gases along with various impurities including water vapor and heavier hydrocarbons. When raw natural gas is withdrawn from the underground reservoirs, the impurities are considered objectionable and are usually removed by various processing methods. Water vapor in natural gas is a very serious problem in gas production because it can cause corrosion and reduce pipeline capacity or block gas flow by condensation or through the formation of hydrates. Many different processes have been invented to remove this objectionable impurity content from gas streams with the most prevailant being glycol reheating processes. These glycol processes are very efficient however they have economical and safety drawbacks. More stringent safety and pollution requirements have prevented the use of glycol dehydration units in certain applications due to the requirement of the direct fired reboiler needed for the operation of the process. Further, within a remote location it would be uneconomical to locate a glycol dehydration unit due to the need for a fuel supply and other associated requirements.
In recent years there has been an increased interest in utilizing non reboiler type processes, such as calcium chloride brine dehydrators. Dehydration of a gas stream utilizing brine formed from the gas stream contacting a bed of calcium chloride has been taught hereintofore and specifically within my invention covered by U.S. Pat. No. 3,545,177. Due to the environmental requirements and the ever increasing need for more efficient production of energy, there is a need for new and improved designs of calcium chloride dehydration units which have increased gas-brine contacting as well as improved bed design to avoid bridging and channeling of the material.